in the Pilot she was also like 20 years old. Most people fill out a little once they hit the late 20's.

She's by no means fat, but she's also, not a kid anymore.

Oh, for sure. She is still bigger than the first few season, but must have starved herself knowing this scene was coming because there is a difference from the previous episodes this season.

This happens a lot on shows. Look at Cobie Smulders. That first season of HIMYM... she was the hottest woman on TV. Then she had a kid. Believe me she is hot now, I just wish she did her Maxim shoot when she was a 10, not a 9.9. Same could be said with cupcake girl all these years later on that show.